Describe how Avogadro's number is related to a mole of any substance?

The relationship is that Avogadro's number is the exact number of atoms / molecules / Ions of a certain substance that creates exactly 1 mole.

One mole of any substance contains ##6.022 * 10^(23)## atoms, ions, or molecules of that substance.

Just like how there's 12 in a dozen or 2 in a pair. 4 Dozens would be 48. 4 Pairs would be 8.

Avogadro's number (##6.0221413 * 10^(23)##) is the number that defines a single mole.

4 Moles would be ##4 * (6.0221413 * 10^(23))##

To use moles in science is fairly similar to using dozen or pairs.

A dozen fluorine atoms is 12. A pair of fluorine atoms is 2. A mole of fluorine atoms is ##6.0221413 * 10^(23)##

Moles is just a standard way of quantifying the number of atoms because counting atoms themselves is simply impossible.